This disclosure relates generally to hydrocarbon exploration and production, and in particular to forming wellbore tubular strings and connections to facilitate hydrocarbon production or downhole fluid injection.
During hydrocarbon exploration and production, a wellbore typically traverses a number of zones within a subterranean formation. A tubular system may be established in the wellbore to create flow paths between the multiple producing zones and the surface of the wellbore. Efficient completion of the wellbore or production from the surrounding formation is highly dependent on the inner diameter of the tubular system installed in the wellbore. Greater inner diameters of the tubular string allows inserted equipment and fluids with appropriate pressure ratings to be used in well completions, while also allowing increased production of hydrocarbons thereafter.
Expandable tubing may be used to increase the inner diameter of casing, liners and other similar downhole tubular strings used as described above. To create a casing, for example, a tubular member is installed in a wellbore and subsequently expanded by displacing an expansion device through the tubular member. The expansion device may be pushed or pulled using mechanical means, such as by a support tubular coupled thereto, or driven by hydraulic pressure. As the expansion device is displaced axially within the tubular member, the expansion device imparts radial force to the inner surface of the tubular member. In response to the radial force, the tubular member plastically deforms, thereby permanently increasing both its inner and outer diameters. In other words, the tubular member expands radially. In certain operations, expandable tubulars may be used to repair, seal, or remediate existing casing that has been perforated, parted, corroded, or damaged since installation.
In some circumstances, after the radial expansion and plastic deformation process, the expansion tools and any other tools associated therewith may need to be removed to the surface of the wellbore. Some operations include a separate trip into the wellbore, wherein a retrieval tool is lowered and coupled to the expansion tools for retrieval to the surface. In other operations, the upper unexpanded tubular string and the tools coupled thereto are separated from the lower expanded and installed tubular string for removal to the surface. To separate the unexpanded tubular string from the expanded tubular string, a cutter is used. A casing cutter may be part of the initial tool string such that the casing may be cut without an additional trip. However, the cutter operation is time-consuming and creates collateral damage to the casing. Therefore, in certain operations, utilized a casing cutter may not be acceptable.
There remains a need in the art for providing a reliable, simple apparatus and process for releasing a section of expanded tubing from unexpanded tubing. The principles of the present disclosure are directed to overcoming one or more of the limitations of the existing apparatus and processes for separating expanded tubing from unexpanded tubing and associated tools.